Storage area networks (“SANs”) are known in the art. In general, a storage area network includes data storage devices, such as disk array controllers and tape libraries, attached to servers, commonly referred to as host computers (“hosts”), via a communication infrastructure, such as a switching fabric. A storage area network also includes a SAN-management application, which organizes the connections in the communication infrastructure, the storage devices, and host computers so that data transfers are secure and robust. An important characteristic of a storage area network is that the storage devices are generally available to multiple hosts at the same time, which helps make a storage area network scalable and flexible. A typical SAN architecture works in a way that makes all storage devices available to all host computers on a LAN or WAN.
The host computers of a respective storage area network access data stored in respective data storage devices on behalf of client computers that request data. For example, according to conventional techniques, upon receiving a storage access request, a respective host computer in a storage area network accesses a large repository of storage through a switching fabric on behalf of a corresponding requesting client. An access can include a read or write of data to storage.
Typically, many clients can access data through the same host computer or server. Thus, storage area networks enable multiple clients to access one or more shared storage systems through the same host computer. In many applications, storage area networks support hi-speed acquisitions of data so that the host servers are able to promptly retrieve and store data from the data storage system.
A respective infrastructure supporting access to data in a storage area network can be quite complex. Numerous hardware and software components must work in harmony in order for a user to successfully access data stored in a storage array of a storage area network. To access such data, a user application provides file system calls or requests (e.g., open, read, write and so forth) to a file system resource presented to the user application by an operating system executing on the host computer system. The file system receives the file system calls and operates to map such file system calls to a series of I/O requests. The operating system on the host computer system transmits the I/O requests through a host interface device resource, such as an interface card (e.g., SCSI or FibreChannel adapter) having one or more I/O port resources, across an interface cable or networking medium of one or more switches (e.g., in a storage area network implementation) to a front-end adapter interface card resource operating on a high-capacity data storage array of the storage area network. The front-end adapter interface card receives the I/O requests and interprets them to identify appropriate data locations within specific storage device resources contained in the storage array. After the requested data is accessed from the storage devices, respective I/O responses are typically returned from the accessed storage system to the user application along an information or data flow path (based on operations and processing functionality provided by each of the aforementioned components and resources) in a reverse direction back to the application on the host computer running the client application.